// Copyright 2013 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

// Functions for canonicalizing "path" URLs. Not to be confused with the path
// of a URL, these are URLs that have no authority section, only a path. For
// example, "javascript:" and "data:".

#include "url/url_canon.h"
#include "url/url_canon_internal.h"

namespace url {

namespace {

    // Canonicalize the given |component| from |source| into |output| and
    // |new_component|. If |separator| is non-zero, it is pre-pended to |output|
    // prior to the canonicalized component; i.e. for the '?' or '#' characters.
    template <typename CHAR, typename UCHAR>
    bool DoCanonicalizePathComponent(const CHAR* source,
        const Component& component,
        char separator,
        CanonOutput* output,
        Component* new_component)
    {
        bool success = true;
        if (component.is_valid()) {
            if (separator)
                output->push_back(separator);
            // Copy the path using path URL's more lax escaping rules (think for
            // javascript:). We convert to UTF-8 and escape non-ASCII, but leave all
            // ASCII characters alone. This helps readability of JavaStript.
            new_component->begin = output->length();
            int end = component.end();
            for (int i = component.begin; i < end; i++) {
                UCHAR uch = static_cast<UCHAR>(source[i]);
                if (uch < 0x20 || uch >= 0x80)
                    success &= AppendUTF8EscapedChar(source, &i, end, output);
                else
                    output->push_back(static_cast<char>(uch));
            }
            new_component->len = output->length() - new_component->begin;
        } else {
            // Empty part.
            new_component->reset();
        }
        return success;
    }

    template <typename CHAR, typename UCHAR>
    bool DoCanonicalizePathURL(const URLComponentSource<CHAR>& source,
        const Parsed& parsed,
        CanonOutput* output,
        Parsed* new_parsed)
    {
        // Scheme: this will append the colon.
        bool success = CanonicalizeScheme(source.scheme, parsed.scheme,
            output, &new_parsed->scheme);

        // We assume there's no authority for path URLs. Note that hosts should never
        // have -1 length.
        new_parsed->username.reset();
        new_parsed->password.reset();
        new_parsed->host.reset();
        new_parsed->port.reset();
        // We allow path URLs to have the path, query and fragment components, but we
        // will canonicalize each of the via the weaker path URL rules.
        success &= DoCanonicalizePathComponent<CHAR, UCHAR>(
            source.path, parsed.path, '\0', output, &new_parsed->path);
        success &= DoCanonicalizePathComponent<CHAR, UCHAR>(
            source.query, parsed.query, '?', output, &new_parsed->query);
        success &= DoCanonicalizePathComponent<CHAR, UCHAR>(
            source.ref, parsed.ref, '#', output, &new_parsed->ref);

        return success;
    }

} // namespace

bool CanonicalizePathURL(const char* spec,
    int spec_len,
    const Parsed& parsed,
    CanonOutput* output,
    Parsed* new_parsed)
{
    return DoCanonicalizePathURL<char, unsigned char>(
        URLComponentSource<char>(spec), parsed, output, new_parsed);
}

bool CanonicalizePathURL(const base::char16* spec,
    int spec_len,
    const Parsed& parsed,
    CanonOutput* output,
    Parsed* new_parsed)
{
    return DoCanonicalizePathURL<base::char16, base::char16>(
        URLComponentSource<base::char16>(spec), parsed, output, new_parsed);
}

bool ReplacePathURL(const char* base,
    const Parsed& base_parsed,
    const Replacements<char>& replacements,
    CanonOutput* output,
    Parsed* new_parsed)
{
    URLComponentSource<char> source(base);
    Parsed parsed(base_parsed);
    SetupOverrideComponents(base, replacements, &source, &parsed);
    return DoCanonicalizePathURL<char, unsigned char>(
        source, parsed, output, new_parsed);
}

bool ReplacePathURL(const char* base,
    const Parsed& base_parsed,
    const Replacements<base::char16>& replacements,
    CanonOutput* output,
    Parsed* new_parsed)
{
    RawCanonOutput<1024> utf8;
    URLComponentSource<char> source(base);
    Parsed parsed(base_parsed);
    SetupUTF16OverrideComponents(base, replacements, &utf8, &source, &parsed);
    return DoCanonicalizePathURL<char, unsigned char>(
        source, parsed, output, new_parsed);
}

} // namespace url
